man3/unlocked_stdio.3

   1 .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>.
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  25 .TH UNLOCKED_STDIO 3  2017-09-15 "" "Linux Programmer's Manual"
  26 .SH NAME
  27 getc_unlocked, getchar_unlocked, putc_unlocked,
  28 putchar_unlocked \- nonlocking stdio functions
  29 .SH SYNOPSIS
  30 .nf
  31 .B #include <stdio.h>
  32 .PP
  33 .BI "int getc_unlocked(FILE *" stream );
  34 .B "int getchar_unlocked(void);"
  35 .BI "int putc_unlocked(int " c ", FILE *" stream );
  36 .BI "int putchar_unlocked(int " c );
  37 .PP
  38 .BI "void clearerr_unlocked(FILE *" stream );
  39 .BI "int feof_unlocked(FILE *" stream );
  40 .BI "int ferror_unlocked(FILE *" stream );
  41 .BI "int fileno_unlocked(FILE *" stream );
  42 .BI "int fflush_unlocked(FILE *" stream );
  43 .BI "int fgetc_unlocked(FILE *" stream );
  44 .BI "int fputc_unlocked(int " c ", FILE *" stream );
  45 .BI "size_t fread_unlocked(void *" ptr ", size_t " size ", size_t " n ,
  46 .BI "                      FILE *" stream );
  47 .BI "size_t fwrite_unlocked(const void *" ptr ", size_t " size ", size_t " n ,
  48 .BI "                      FILE *" stream );
  49 .PP
  50 .BI "char *fgets_unlocked(char *" s ", int " n ", FILE *" stream );
  51 .BI "int fputs_unlocked(const char *" s ", FILE *" stream );
  52
  53 .B #include <wchar.h>
  54 .PP
  55 .BI "wint_t getwc_unlocked(FILE *" stream );
  56 .B "wint_t getwchar_unlocked(void);"
  57 .BI "wint_t fgetwc_unlocked(FILE *" stream );
  58 .BI "wint_t fputwc_unlocked(wchar_t " wc ", FILE *" stream );
  59 .BI "wint_t putwc_unlocked(wchar_t " wc ", FILE *" stream );
  60 .BI "wint_t putwchar_unlocked(wchar_t " wc );
  61 .BI "wchar_t *fgetws_unlocked(wchar_t *" ws ", int " n ", FILE *" stream );
  62 .BI "int fputws_unlocked(const wchar_t *" ws ", FILE *" stream );
  63 .fi
  64 .PP
  65 .in -4n
  66 Feature Test Macro Requirements for glibc (see
  67 .BR feature_test_macros (7)):
  68 .ad l
  69 .in
  70 .PP
  71 .BR getc_unlocked (),
  72 .BR getchar_unlocked (),
  73 .BR putc_unlocked (),
  74 .BR putchar_unlocked ():
  75 .RS 4
  76 /* Since glibc 2.24: */ _POSIX_C_SOURCE\ >=\ 199309L
  77     || /* Glibc versions <= 2.23: */ _POSIX_C_SOURCE
  78     || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
  79 .RE
  80 .PP
  81 .BR clearerr_unlocked (),
  82 .BR feof_unlocked (),
  83 .BR ferror_unlocked (),
  84 .BR fileno_unlocked (),
  85 .BR fflush_unlocked (),
  86 .BR fgetc_unlocked (),
  87 .BR fputc_unlocked (),
  88 .BR fread_unlocked (),
  89 .BR fwrite_unlocked ():
  90 .RS 4
  91 /* Glibc since 2.19: */ _DEFAULT_SOURCE
  92     || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
  93 .RE
  94 .PP
  95 .BR fgets_unlocked (),
  96 .BR fputs_unlocked (),
  97 .BR getwc_unlocked (),
  98 .BR getwchar_unlocked (),
  99 .BR fgetwc_unlocked (),
 100 .BR fputwc_unlocked (),
 101 .BR putwchar_unlocked (),
 102 .BR fgetws_unlocked (),
 103 .BR fputws_unlocked ():
 104 .RS 4
 105 _GNU_SOURCE
 106 .RE
 107 .ad b
 108 .SH DESCRIPTION
 109 Each of these functions has the same behavior as its counterpart
 110 without the "_unlocked" suffix, except that they do not use locking
 111 (they do not set locks themselves, and do not test for the presence
 112 of locks set by others) and hence are thread-unsafe.
 113 See
 114 .BR flockfile (3).
 115 .SH ATTRIBUTES
 116 For an explanation of the terms used in this section, see
 117 .BR attributes (7).
 118 .ad l
 119 .TS
 120 allbox;
 121 lbw20 lb lb
 122 l l l.
 123 Interface       Attribute       Value
 124 T{
 125 .BR getc_unlocked (),
 126 .BR putc_unlocked (),
 127 .BR clearerr_unlocked (),
 128 .BR fflush_unlocked (),
 129 .BR fgetc_unlocked (),
 130 .BR fputc_unlocked (),
 131 .BR fread_unlocked (),
 132 .BR fwrite_unlocked (),
 133 .BR fgets_unlocked (),
 134 .BR fputs_unlocked (),
 135 .BR getwc_unlocked (),
 136 .BR fgetwc_unlocked (),
 137 .BR fputwc_unlocked (),
 138 .BR putwc_unlocked (),
 139 .BR fgetws_unlocked (),
 140 .BR fputws_unlocked ()
 141 T}      Thread safety   MT-Safe race:stream
 142 T{
 143 .BR getchar_unlocked (),
 144 .BR getwchar_unlocked ()
 145 T}      Thread safety   MT-Unsafe race:stdin
 146 T{
 147 .BR putchar_unlocked (),
 148 .BR putwchar_unlocked ()
 149 T}      Thread safety   MT-Unsafe race:stdout
 150 T{
 151 .BR feof_unlocked (),
 152 .BR ferror_unlocked (),
 153 .BR fileno_unlocked ()
 154 T}      Thread safety   MT-Safe
 155 .TE
 156 .ad
 157 .SH CONFORMING TO
 158 The four functions
 159 .BR getc_unlocked (),
 160 .BR getchar_unlocked (),
 161 .BR putc_unlocked (),
 162 .BR putchar_unlocked ()
 163 are in POSIX.1-2001 and POSIX.1-2008.
 164 .PP
 165 The nonstandard
 166 .BR *_unlocked ()
 167 variants occur on a few UNIX systems, and are available in recent glibc.
 168 .\" E.g., in HP-UX 10.0. In HP-UX 10.30 they are called obsolescent, and
 169 .\" moved to a compatibility library.
 170 .\" Available in HP-UX 10.0: clearerr_unlocked, fclose_unlocked,
 171 .\" feof_unlocked, ferror_unlocked, fflush_unlocked, fgets_unlocked,
 172 .\" fgetwc_unlocked, fgetws_unlocked, fileno_unlocked, fputs_unlocked,
 173 .\" fputwc_unlocked, fputws_unlocked, fread_unlocked, fseek_unlocked,
 174 .\" ftell_unlocked, fwrite_unlocked, getc_unlocked, getchar_unlocked,
 175 .\" getw_unlocked, getwc_unlocked, getwchar_unlocked, putc_unlocked,
 176 .\" putchar_unlocked, puts_unlocked, putws_unlocked, putw_unlocked,
 177 .\" putwc_unlocked, putwchar_unlocked, rewind_unlocked, setvbuf_unlocked,
 178 .\" ungetc_unlocked, ungetwc_unlocked.
 179 They should probably not be used.
 180 .SH SEE ALSO
 181 .BR flockfile (3),
 182 .BR stdio (3)